“There are times when you can sit on the sidelines. This not one of them. I decided I have to get in the fight,” Hulings said in an interview with the Texas Tribune.

San Antonio teacher Rick Treviño joined the race on Friday. Treviño recently ran for city council and narrowly missed a runoff.

In an interview with the Tribune, Treviño, who was backed by the Sen. Bernie Sanders-affiliated Our Revolution, backed left-wing positions such as “Medicare for all,” and a living wage tied to inflation.

“My platform is not going to be tempered by considerations of what corporate donors or the establishment thinks,” Treviño said. “I just know what I’m going to do is stick to my issues, stick to my platform.”

Hurd first won his seat in 2014 when he beat then-Rep. Pete Gallego. Hurd won a rematch with Gallego in 2016 by 1.3 percentage points.

Gallego has been exploring another rematch in 2018, but his spokesman did not give a definite answer to the Tribune about his plans for next year.